METEORITES
The oldest rocks on Earth
Meteorites are rocks that have fallen to Earth from space. When you hold a meteorite in your hand you are actually holding a piece of an asteroid - a piece of rock that was left over from the formation of the Solar System.
Like many rocks on Earth, scientists are able to date meteorites because they contain radioactive elements that decay into other elements at a known rate. In a technique known as radiometric dating the proportions of such elements are measured and an approximate age obtained for the sample. Using this method the vast majority of meteorites are found to be more than 4.5 billion years old. Meteorites are therefore considerably older than any other object on the surface of the Earth.
Most meteorites consist of silicate rock and are called stony meteorites but others are composed of a nickel-iron alloy and are called iron meteorites. Only about 5% of all meteorites that fall to Earth are iron meteorites.
Iron meteorites are thought to originate from the cores of asteroids that were once molten. Most stony meteorites consist of minerals that occur in rocks on the surface of the Earth but there are also groups of minerals that do not occur on Earth. Meteorites are therefore a unique source of information about the formation and early history of the solar system. Most have remained unaltered since they were formed. For these reasons they are of immense scientific value.
Meteorites are named after the place they were found, such as a nearby town or mountain range.
Meteorites and related items for sale
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